Identify what is the account number you are going to create. Because there are restrictions and conventions for creating G/L accounts. Certain ranges is allocated for P&L and some for B/S.
Check with Financial Accounting process owners to give you the account number. If you already know the number, Get the reference G/L account number.
When you go to FS00, enter the new G/L number and click on create with reference icon. Once you are done, Find out in which account group, does the RENT line belong to. You may be able to enter that name of the group through transaction KDH2. Include the new G/L account under this group.
Upload the new Account group hierarchy to BW. This will ensure that the new G/L account is included under the right hierarchy.